How to Drill a 1 1/2" Hole in Firebrick?

[velvetfoot]

The biggest masonry bit at the hardware store is 1".
I tried a hole saw meant for wood, figuring it was about 5 bucks and thought it'd might be a one-time use thing - I can see now why it was meant for wood. I got maybe an 1/8" deep and the points were already ground down pretty well.
I tried drilling a bunch of little holes and then tried chiseling it out, but that just broke the brick.
My current plan to to try to get the brickyard to do it.

Any ideas?

I have a RotoZip, but I'm not sure if that's the right tool.

 

[EatenByLimestone]

Masonry bit on a jig saw? How smooth do the edges have to be?

Matt

 

[KeithO]

You need a "core drill". Basically a pipe with either carbide or steel with diamond grit embedded in it and a shaft welded on the end so that you can chuck it.
See here: (broken link removed to http://www.southern-tool.com/store/mq_core_bits.html)

Often, these drills and bits can be rented by the hour. And if you are drilling firebrick, you might take all the ones you want drilled to the rental place and see if you can do it right there.

An alternative is to notch the brick instead with an abrasive cutoff wheel. Then chisel out the bit between the notches and after installing, fill in with refractory cement.

 

[velvetfoot]

Not too smooth-it's for an air pipe at the back of the insert.
I didn't know there was such a thing as a jig saw blade for masonry.

 

[velvetfoot]

Not too smooth-it's for an air pipe at the back of the insert.
I didn't know there was such a thing as a jig saw blade for masonry.

 

[velvetfoot]

Thanks.
Maybe I could use the roto zip or dremel.

 

[elkimmeg]

Even if you get threw the fire brick it should be backed by considerable amounts of masonry.

Your hone owner tools were never made to do this job go to the rental store and rent a commercial hammed drill and bit

Or you are just wasting your time Mind if I chuckle about the dremel and roto zip tool Sorry just think about it is too funny

 

[karl]

Get a hammer drill and few smaller bits. Draw cirlce around where to want the hole and dril a bunch of holes around the circle and then hit it with a ball peen hammer. A regular drill is a waste of time. Harbor freight has some cheap hammer drills. I don't know how good they are but I can tell you a hammer drill will amaze you the first time you use it. With out the right sized bit its going to be a pain but you can get it done.

Oh and elk. I love the dremel slogan. "It will kinda do a 1000 different jobs."

 

[Gooserider]

Is this trying to make a hole in firebrick that is already mortared in place, or make a hole in some firebrick for something you are building?

If it's existing masonry, you probably don't have much choice other than to rent a core drill as suggested earlier.

If you are building something, I'd consider trying to split the brick, hollow out each half, then mortar the peices back together. Another alternative might be to lay bricks around the pipe, then "cast" it in place by filling the hole w/refractory cement.

I don't think you could get through a full brick w/ a rotozip or a dremel, neither offers a bit that would be long enough, not to mention that they wouldn't have the power for the job. They do make saber-saw blades that are supposed to work on tile, stone, and other such materials - usually they have an abrasive coating on them, but I don't know if they'd be long enough.

Gooserider

 

[Burn-1]

I think a diagram would help. I grabbed this from my manual.

I am trying to do the same thing and have been thinking the hammer drill route.
I've attached the diagram from the Isle Royale which is what I am using and working
over replacing the firebricks since like others I'm not too happy with the low density
brick used by Quadrafire.

The two 1.5 inch holes are needed for the rear air intakes, shown as brick 5 in the diagram.

 

[Gooserider]

OK that makes more sense now that you've given us a picture. The brick yard may be able to drill the bricks for you, as mentioned - if they can, it probably would be the lowest hassle approach. I still don't think a dremel would do it, and seriously doubt that a roto-zip could either. A hammer drill w/ a small bit might work, or you might be able to use one of those masonry sabersaw bits that I mentioned earlier.

Gooserider

 

[EatenByLimestone]

Small holes around the circumference of the circle and then careful tapping?

Matt

 

[elkimmeg]

No drilling required why not make up a mold the exact same size mix up refractory concrete and use a 1.5" pipe for the hole location a same as the existing brick when fairly hard tap out that pipe and there is your hole. Hint the pipe you use coat it with grease, WD-4-, motor oil so that it taps out easily

For that matter re use the molds to make all your bricks

 

[jqgs214]

Elk to the rescue again. Love that plan. Will use it when I need to replace my bricks. Unless tom can sell em cheaper!

 

[mtarbert]

Water cooled diamond coated core drill is the best way. Hint: when drilling back the brick up with a rubber pad,this will cut down on the vibrations that tend to crack the brittle bricks.
Mike

 

[BrotherBart]

Buy the pumice ones with holes in them from Quad and replace the rest with regular ceramic firebrick.

 

[Burn-1]

I already tried that and wouldn't you know? They make you buy the whole set for something like $100, plus shipping.

Not kidding.

 

[velvetfoot]

The brickyard wouldn't do it.
I got a 1" masonry bit from the hardware store, drilled the hole, and then wiggled it around to get a bigger hole.
It worked. I now have nice hard, smooth fire brick.
I could have rented a core boring machine for $35 bucks, but the drill was $14 and I get to keep it.
The place I bought it from said it was okay to use that brick.
Also said it sounded like creosote and to make sure I burn it hot sometimes.
Now I am ready for fire!
Oh wait, I have to move some wood around, don't I?

 

[jtp10181]

I already tried that and wouldn't you know? They make you buy the whole set for something like $100, plus shipping.

Not kidding.

Last time I checked we (as a dealer) can order individual bricks. Especially the ones with the holes, they have their own special part number.

 

[Burn-1]

Last time I checked we (as a dealer) can order individual bricks. Especially the ones with the holes, they have their own special part number.

Then I think I need to find a new dealer because that's what a local shop told me. You have a PM on the way.

 

[idahomike]

I tried a cheap 3/8 masonry bit on standard fire brick and it worked very well to mine out the center and perimeter of the 1 1/2 inch hole I needed. I have a quadrafire stove with air nipples in the back. I tried chiseling out the remainder and promptly cracked the brick in half. My standard hole saw made it all the way through the next one I had mined out but was trashed and couldn't cut another brick. Since none of the dealers in my area sold pre drilled bricks I don't feel too bad about ruining the hole saw given the expense of mail order. The dust is pretty hard on the throat and eyes.